Tunneling Overview!

Tunneling is the basis of VPN .  Almost all the VPN works on the method called tunneling.Tunneling is the method of used to transfer data from one network over another network in Network Infrastructure. The data to be transferred can be in frames of another protocol.

Tunneling encapsulates the data send by the sending node on its format i.e it adds its header, which contains routing information so that the data is traveresd in the network properly.The encapsulated packets are routed through the endpoint of the tunnel over the network. Tunnel is the logical path through which the packets encapsulated are traversed to reach the destination. when the frames reaches the destination the packet is de-encapsulated and the frames are forwarded to the final destination.

In short tunneling is the process of outlined below

Frames ——> Encapsulation ——> Transmission ——>  De-encapsulation ——> Destination

Protocols used by tunneling.

Tunneling uses one type of protocol to encapsulate the frames from the datagram of protocol. VPN uses PPTP protocol to encapsulate the frame over the internet(public network). Alternative  protocol which can be used is L2TP. This protocols depends upon the features specified by the PPP. PPP was the basic protocol used to send data across dedicated or dial-up connections. PPP encapsulates the IP packets with the PPP frames and transmits the data across the network. It was specifically designe to be used over NAS ( Network Access Server).

Tunneling requires three protocols.

Carrier - The protocol used by the network to tranfer the data.

Encapsulating protocol — the protocol to wrap the data.(PPTP,L2TP,GRE,IPSec)

Passenger protocol - protocol to carry the original data(IPX, Netbeui,IP).

What is split tunneling?

split tunneling is the method which enables the Remote access VPN CLIENTS to route the corporate traffic over the network(VPN connection),while sends the Internet based traffic using the local Internet connection. This is great method to split the traffic, use of corporate bandwidth for access to internet sitesis prevented.

This adds the extra security to the network. If the remote access client has the reachability to both Internet and private Organisation network simultaneously, there is the possiblity that the Internet connection can be exploited to access to private organisation network through the remote access client.

The companies which are more security sensitive can choose to use the default routing method which ensures that every traffic by the VPN client passes by the corporate firewall.

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VPN is a network is a network which is formed using public wires to connect nodes i.e we can say that itis private network which makes use of public newtork,which allows you to secure your network through security and encryption policies.
It provides additional security to the network and also remote access into the enterprise.VPN is boon for the network professional and the enterprneurs. It gives the business the alternative to an expensive dedicated private connection from one office to another. many of them uses

VPN on their serves to allow employees to remotely login to the server.VPN adds an advantage to the the existing network which is File sharing, Video conferencing and many more similar network services. It doesn’t allow any new functionality that is offered by the alternative network mechanisms, however you can get these services offered in more configured , secured andefficiently managed and the most important is VPN is Cheap in most of the cases.

VPN uses the method called as tunneling , it uses the same hardware as the exsisting network (Internet/Intranet).

VP suports at least 3 modes of use:

Remote access
LAN to LAN Internetworking
Controlled access in Intranet.

Pros and cons of Virtual private network:

Pros:
VPN is one of the network solution which establish Long- distance secured connections, particularly for wireless local area networking.

VPN is cost effective: It saves the money for the organisations in many aspects .It eliminates the need for Long distance Leased lines. - Many organization uses T1 lines traditionaly to office locations, VPN allows you to use the publivc network infrastructure including internet to make theseconnections and make it a private virtual network thorugh a chepaer local leased lines or may be by using Broadband connections from the nearer ISP.

Reduces long distance telephone charges: A VPN replaces the remote servers and long distance connections used commonly.Here, the client needs to connect nearer ISP which is at the low cost ascompared to the previosly used method.
Reducing support costs: It reduce the cost for the organization to maintain the network. The organisation can hire a third party servie providers.
Scalabitlity: The cost of scaling up the netwotk in the dedicated Network is much more higher as compared to the VPN.

Using VPN is also vey easy if you have the appropriate networking software and hardware support..

VPN have some Limitations too:

Although it seems to be a perfect network infrastructure there exists some limitations to it.

1. It needs a complete understanding of the security issues with the carefull installation to ensure the intended security on the public network as internet.

2. When using the internet bases VPN the performance and the reliablity is ot in the hands of theOrganization.

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